Abstract The New Testament, while rejecting any superficial connection between illness and sin, does not reject a possible connection between illness and a person's relationship with God. An example can be seen in the story of the young blind man who was healed (St. John 9:3). His blindness does not result from any fault he or his parents had committed but apparently from God's wish to reveal his own healing power. The inner blindness of the Pharisees is a different type of blindness far more difficult to heal. The blind young man was actually healed, not only in body but also in soul. Such miraculous healings are rare nowadays. However, if one takes a closer look at modern genetics and psycho-neuro-immunological findings, one may come to a better understanding of how miracle healings are linked to man's inner life and therefore also to his religiousness. Many diseases have genetic backgrounds. Defective genes, however, do not necessarily lead to subsequent illness. Genes have to be switched on or off. Only activated genes trigger pathological change. The human brain and all of man's thinking and feeling are intimately connected with such activations. We may thus conclude that both inner life and religious outlook on life are relevant to the origin and development of diseases.